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(11) | EP 0 272 142 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Magnetic field enhanced plasma etch reactor |
| (57) A magnetic field enhanced single wafer plasma etch reactor (60) is disclosed. The
features of the reactor include an electrically-controlled stepped magnetic field
for providing high rate uniform etching at high pressures; temperature controlled
reactor surfaces including heated anode surfaces (walls and gas manifold) and a cooled
wafer supporting pedestal/cathode (70,72); and a unitary wafer exchange mechanism
(74) comprising wafer lift pins (79) which extend through the pedestal and a wafer
clamp ring (78). The lift pins and clamp ring are moved vertically by a one-axis lift
mechanism (140) to accept the wafer from a co-operating external robot blade (76),
clamp the wafer to the pedestal and return the wafer to the blade. The electrode cooling
combines water cooling for the body of the electrode (70) and a thermal conductivity-enhancing
gas interface between the wafer and electrode for keeping the wafer surface cooled
despite the high power densities applied to the electrode. A gas feed-through device
(114, 175, 176) applies the cooling gas to the RF powered electrode (72) without breakdown
of the gas. Protective coatings/layers (81,83) of materials such as quartz are provided
for surfaces such as the clamp ring and gas manifold. The combination of these features
provides a wide pressure regime, high etch rate, high throughput single wafer etcher
wich provides uniformity, directionality and selectivity at high gas pressure, operates
cleanly and incorporates in-situ self-cleaning capability. |